Data transaction card and method of manufacture thereof

ABSTRACT

A data transaction card having an interface for bi-directional contactless communication, and comprising a support ( 20 ) having a cavity ( 12 ) for accommodating therein a chip carrier therein module ( 10 ). The chip carrier module comprises a substrate ( 11 ) having a first side ( 45 ) and a second side ( 46 ), and an integrated circuit ( 30 ) mounted on the first side of the substrate for managing functions of the data transaction card. A coil antenna ( 40 ) is electrically connected to the integrated circuit for inductive coupling with remote antenna, connections to the coil antenna being accessible from the first side of the substrate. The chip carrier module is packaged into one discrete unit so as to be amenable to mechanical assembly of the data transaction card without requiring additional electrical connections between the support and the chip carrier module during or subsequent to assembly. Such a construction allows for efficient mass-production of the data transaction card.

CROSS REFERENCE TO RELATED APPLICATION

The present application is the national stage under 35 U.S.C. 371 ofPCT/IL98/00543, filed Nov. 9, 1998.

FIELD OF THE INVENTION

The invention relates to a bi-directional communication data transactioncard with an onboard processor for effecting both “contact” and“contactless” modes of data transfer.

BACKGROUND OF THE INVENTION

Both “contact” and “contactless” bi-directional communication datatransaction cards are known per se. A concise introduction to thenomenclature and principal features of data transaction cards, alsocalled data cards or smart cards, is found in an IEEE Conference Paperby Klaus Vedder, The Hague, May 4-8, 1992, hereinafter referred to asVedder. Another general overview is given by Gilles Lisimaque in a papercalled “Smart Cards” delivered at the 27th. International SAMPETechnical Conference, Oct. 9-12, 1995. Smart cards represent a specificimplementation of chip cards wherein the chip is a microcomputer havinga programmable memory.

Generally, such smart cards are provided either with electrical contactsfor effecting direct electrical contact with a card reader, or with anantenna coil for effecting contactless bi-directional communication witha remote card reader. U.S. Pat. No. 5,206,495 for a Chip Card in thename of H. D. Kreft discloses a chip card allowing both contact andcontactless communication in a single smart card.

A principal object of U.S. Pat. No. 5,206,495 is the provision of a chipcard including both a contact field and transmission coils and aswitching element device coupled between both and a semiconductor devicesuch as a microcomputer.

International Patent Publication No. WO 98/29830, in the name of thepresent applicant, discloses a contact/contactless data transaction cardwhich automatically conforms to a required communication mode inaccordance with whether data is received via the antenna or via thecontacts.

Contactless smart cards are particularly suited for applications, suchas mass transport systems, wherein data communication must be effectedvery quickly without imposing the overhead incurred in manuallyintroducing the smart card into the slot of a card reader.

Common to all such smart cards is an on-board microcomputer including amemory and processing capability for effecting the desiredbi-directional data transmission and data storage. In the case where“contact” data transmission is required, there is provided a so-called“contact field” having a plurality of contacts, each of which isconnected to the microcomputer by means of a respective electricalconnection. Data transmission with an external reader is then effectedby inserting the card into a suitable reader having a spring-loadedcontacts which bear on the respective contacts in the contact field ofthe chip card.

Alternatively, when contactless data transmission is required, anantenna coil in the chip card is adapted to receive data from andtransmit data to a reading device having a similar antenna.

Sometimes, such contact/contactless cards are called hybrid cards. Thesecards are thus packaged, with at least, components such as contacts, amicrocomputer and an antenna.

As smart cards are presently mass-produced by the hundreds of millions,the assembly of the components and their embedding and packaging intothe cards must be performed by fast and cost-effective processes. Forpurposes of compatibility, international standards govern the smart cardindustry. Thus, the dimensions and the location of the contacts of smartcards are laid down by Part 2 of the International Standard ISO 7816.The card itself, known as “standard identification card” or “ID-1 card”,is the size of a regular credit card. The thickness of the card isapproximately 0.8 mm.

The ISO 7816 standard defines eight contacts, in two columns of four,but typically, only five or six are put to use. The other two or threeare reserved for future utilization and therefore often not provided.Each single contact measures at least 2×1.7 mm. The eight contacts ofthe contact field are contained in a square of about 10×10 mm, thuscovering an area of about 1 cm². FIG. 1a provides the minimum dimensionsof the contacts, their arrangement and their location in the upper leftcorner of a card, as dictated by the ISO 7816. standard. FIG. 1b givesan example of a contact field with an eight contact layout. Themicrocomputer or integrated circuit used in a data transaction card isusually integrated on to a single piece of silicon. The size of a chipgenerally only extends from some 1 mm² to 16 mm², with a thicknessranging from 0.1 to 0.2 mm.

Typically, the antenna coil is wound around the periphery of the card,thus having dimensions approximately equal to those of the card andbeing very much greater than those of the contact field. As a result,the contacts induce no deleterious effect on the operability of theantenna coil. This, however, is not the case when the antenna coil isreduced in size so as to allow for its mounting directly on theintegrated circuit. In such case, the close proximity of the mass ofmetal constituted by the contact field to the antenna coil, caninterfere with its operability.

Different designs have been devised for the assembly of the manycomponents of a smart card into a finished product. For example, U.S.Pat. No. 5,589,032 in the name of J-C. Fidalgo provides a bi-directionalcontact and contactless communication card. Fidalgo describes all thenecessary components and suggests ways to facilitate their assembly,their electrical connection and their final integration. Nevertheless,the assembly still requires the laborious addition of components both inthe body of the card 2, as well as in the electronic module 7. Forexample, the antenna 5 is embedded in the body of the card 2 and must beconnected to the chip 8 which is itself part of the electronic module 7.Thus the different discrete components must be electricallyinterconnected. Thus, the card described by Fidalgo is not based onmodular building blocks which are amenable for mass assembly.

To alleviate the difficulties encountered with the assembly andconnection of the antenna, German Patent No. 37 21 822, in the name ofK. Sickert, proposes forming the coil antenna 4 on to the semiconductorof the Integrated Circuit 5, around the active surface of thesemiconductor and along its borders. Such a scheme allows the antenna tobe provided during the manufacture of the integrated circuit and thusobviates the need electrically to connect the antenna to the integratedcircuit in an independent subsequent stage of assembly. However, Sickertlimits his invention to the antenna-chip pair and does not deal withfurther components. Also, since the size of the antenna is necessarylimited by the dimensions of the semiconductor wafer, the transmissionrange is short.

In International Patent Publication No. WO 96/35190, to Reiner, there issuggested a method for contactless inductive coupling of a small antennato a larger one. As an improvement upon Sickert, a small antenna, alongthe edges of a substrate, is inductively coupled to a larger antenna,disposed along the edges of the card itself.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a data transaction cardconstructed by assembly of the body of a card with a chip carriermodule.

It is a further object of the invention to provide such a data cardwherein all the electronic components reside in the chip carrier module,so that no additional electrical connections are required between thecoil antenna and the chip carrier module.

In accordance with a broad aspect of the invention there is provided adata transaction card having an interface for bi-directional contactlesscommunication, the data transaction card comprising:

a support having a cavity for accommodating therein a chip carriermodule which comprises:

a substrate having a first side and a second side,

an integrated circuit mounted on the first side of the substrate formanaging functions of the data transaction card, and

a coil antenna electrically connected to the integrated circuit forinductive coupling with a remote antenna, connections to the coilantenna being accessible from the first side of the substrate;

the chip carrier module being packaged into one discrete unit so as tobe amenable to mechanical assembly of the data transaction card withoutrequiring additional electrical connections between the coil antenna andthe chip carrier module during or subsequent to assembly.

Preferably, the chip carrier module hosts an optical visualauthentication mark, such as an encoded hologram, formed into apersonalized identification mark by insertion of a picture of the bearerof the card as the encoded hologram.

Preferably, the contact/contactless data transaction card furthercomprises a contact field for contact communication, wherein the cardand the contacts are compatible with the 1S0 7816 Standard for contactcards. The contact field includes separate contacts applied on thesecond side of the substrate, for contact communication between the datatransaction card and a card reader.

Preferably, the contact/contactless data transaction card is assembledby use of the conventional methods employed for the production ofcontact data cards.

In accordance with a preferred embodiment, the antenna comprises morethan one winding applied either on the first or second side of thesubstrate. Alternatively, two antennae may be provided each on anopposite side of the substrate and having the same or a different numberof windings. In such case, the two antennae behave as a parallel platecapacitor whose capacitance may be exploited to adjust an operationalfrequency of a tuned circuit containing the coil antennae. If desired,such tuning may be realized by an external capacitor coupled to thesubstrate.

Furthermore, it is also preferable for the windings of the coil antennato be applied along the periphery of the substrate.

The invention also contemplates a method for manufacturing a datatransaction card, method comprising the steps of:

(a) providing a support having a cavity therein,

(b) independently producing a chip carrier module having embeddedtherein an integrated circuit and a coil antenna electrically connectedto said integrated circuit without requiring additional electricalconnections between the coil antenna and the chip carrier module duringor subsequent to assembly without requiring additional electricalconnections between the coil antenna and the chip carrier module duringor subsequent to assembly, and

(c) mounting the chip carrier module in the cavity of the support.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carriedout in practice, a preferred embodiment will now be described, by way ofnon-limiting example only, with reference to the accompanying drawings,in which:

FIG. 1a shows some of the standard dimensions for known contact datacommunication cards, as dictated by the ISO 7816;

FIG. 1b shows an example of a known contact field with an eight contactlayout, as used for contact data communication cards;

FIG. 2 shows schematically a cross-section of a contactless datacommunication cards according to a first embodiment of the invention;

FIG. 3 shows schematically a lower plan view of a substrate for acontactless data communication card according to the invention;

FIG. 4 shows schematically a cross-section of a contactless datacommunication card in accordance with of a second embodiment of theinvention conforming to the layout depicted in FIG. 2;

FIG. 5 shows schematically a cross-section of a contact and contactlessdata communication card in accordance with a third embodiment of theinvention;

FIG. 6 shows schematically a lower plan view of a substrate for thecontact and contactless data communication card illustrated in FIG. 5;and

FIG. 7 shows schematically the contact and contactless datacommunication card shown in FIG. 5 in accordance with a fourthembodiment of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 2 shows a cross-section of a data card according to the presentinvention having a communications interface for allowing a contactlessmode of bi-directional data transmission. The data card includes a chipcarrier module 10 having a substrate 11 which is retained in a cavity 12of a support medium depicted generally as 20.

The substrate 11 provides a foundation for the various components of thecard such as an integrated circuit 30 and a coil antenna 40 which aremounted on a lower surface 45 of the substrate 11 (constituting a firstside thereof). The integrated circuit 30 manages the various command andcontrol functions of the data transaction card. The coil antenna 40 islikewise formed on the lower side 45 of the substrate 11 around theintegrated circuit 30. It is understood that the substrate 11 is aPrinted Circuit Board (PCB) on to which the antenna 40 may be etched inknown manner. The antenna 40 may also be applied on to the lower side 45of the substrate 11 by other means, such as deposition, or wires and thelike. The leads of the antenna 40 terminate with conductive pads (notshown), by means of which the antenna 40 may be connected to theintegrated circuit 30 as will be explained in greater detail below.During a subsequent stage of manufacture following formation of the coilantenna 40, the integrated circuit 30 is mounted on to the lower side 45of the substrate 11 and secured thereto. The coil antenna 40 may haveone or more turns, in a single or multiple layers, according to therequirements for inductive coupling communication between the data cardand a suitable remote card reading device.

FIG. 3 is a plan view of the lower surface 45 of the substrate 11,showing the antenna 40 electrically connected to the integrated circuit30 by two wire leads 17. The electrical connections may be performed bywire bonding or any suitable technique. The next step in the productionprocess calls for the sealing of the connections, a method well known inthe trade. The substrate 11 together with the associated components andthe antenna 40, now packaged into a single discrete unit, constitutesthe chip carrier module 10, ready for integration with the support 20forming the body of data transaction card by mechanical assembly,without requiring any further electrical connections.

The chip carrier module 10 is thus inserted in the cavity 12 until ashoulder 14 of the substrate 11 abuts a corresponding shoulder of thecard, thereby bringing the upper side of both card 20 and the chipcarrier module 10 flush with each other. The chip carrier module 10 isretained within the cavity 12 by gluing or other processes, according tothe finishing steps known in the trade.

FIG. 4 shows an optically encoded visual authentication mark 16 which isnow applied to an upper surface 46 of the substrate 11 (constituting asecond side thereof). The visual authentication mark 16 may be realizedas a hologram or an encoded hologram and allows form visible inspectionfrom the outer surface of the card. The visual authentication mark 16may serve as a personal identification relating to a bearer of the datacard. For example, an encoded hologram with the picture of theproprietor of the data card permits simple visual inspection of theauthorized owner.

As also seen in FIG. 4, the visual mark 16 is applied to the substrate11 and assembled in the chip carrier module 10. The assembly process ofthe chip carrier module 10 comprises the additional step of securing orinscribing the visual mark 16 on to the substrate 11. If the thicknessof the visual mark 16 is not negligible, then account must be takentherefor either by making the substrate 11 thinner or by deepening thecavity 12, in order that the overall thickness of the card conforms tothe requisite standards. This is of particular importance when the datacard is also provided with a contact field for insertion into a slot ofan external card reader, since the slot is dimensioned to accept onlysuch data cards as meet the requisite standards.

FIG. 5 shows in cross-section an application of the invention to a datacard still having both a contactless interface and a contact fieldwhilst still obviating the need for effecting supplementary electricalinterconnections during assembly. To the extent that many of thecomponents in the contact/contactless card are the same as in thecontactless card described above, identical reference numerals will beemployed.

The support medium 20 of the card supports a chip carrier module 10retained in a cavity 22 of the card, and which is complementary in shapeto the chip carrier module 10. The chip carrier module 10 comprises thesubstrate 21 on which the various components of the card are mounted.The substrate 21 has a lower surface (constituting a first side), foraccommodating therein an integrated circuit 30. As will be explained ingreater detail below, the substrate 21 is also provided with several viaholes 26 connecting between the lower surface of the substrate to anupper surface thereof (constituting a second side). The substrate 21further has shoulders 27 for mating with corresponding shoulders in thesupport medium 20 of the card.

The substrate 21 is produced by any of the well-known Printed CircuitBoard manufacturing techniques which provide for the necessaryconductors and via holes. The via holes 26 allow for the electricalconnection of a coil antenna 40 on the lower surface of the substrate 21to respective contacts 31 of a contact field on the upper surface of thesubstrate 21, as will now be explained in greater detail.

The first step of the assembly process requires that the substrate 21 befitted on the lower surface with a coil antenna 40, applied on the flatarea of the shoulders 27. The coil antenna 40 allows for inductivecoupling communication with an appropriate remote antenna in a cardreader (not shown). The coil antenna 40 may have one or more turns, aswell as more than one layer, according to the particular implementationfor which the card is intended. To facilitate the electrical connectionof the coil antenna 40 to the integrated circuit 30 in later productionsteps, the ends of the antenna 40 terminate in conductive pads (notshown in FIG. 5), suitably located in the proximity of the integratedcircuit.

The first step of the assembly process requires that there be applied tothe upper surface of the substrate 21 the contact field including up toeight separate contacts, some of which may be redundant in specificapplications. The emplacement and the size of the contact field on thesupport medium 20, as well as the size and configuration of the separatecontacts, are preferably in accordance with ISO 7816. The via holes 26,which are located, in this example, surrounding the integrated circuit30, are also aligned with, and electrically connected to, the separatecontacts 31. By such means, the coil antenna 40 may be connected to thecontact field 32 even though they are on opposite sides of theintegrated circuit 30. The contact field is dimensioned so as toincrease the effectiveness of the coil antenna 40. Specifically the sizeof the contacts 31 is minimized so that the resulting mass of metal doesnot interfere with the operability of the coil antenna 40.

FIG. 6 shows in plan view the lower surface of the substrate 21illustrating the assembly of the chip carrier module 10. First, the coilantenna 40 is applied to the lower surface of the substrate 21underneath the shoulders 27 which are provided along the edges of thesubstrate 21. The ends of the coil antenna 40 on the shoulders 27 areconnected through conductive leads, to pads (not shown) in the vicinityof the integrated circuit 30, for connection thereto by wire bonding 17.The contact field having six separate contacts 31 (shown in FIG. 5) isnow applied to the upper surface of the substrate 21.

This having been done, the integrated circuit 30 is located and securedon the lower surface of the substrate 21, whereupon the integratedcircuit 30 is electrically connected to the contacts 31 and to theantenna 40 by electrical wire connections 17, using wire bonding. Wirebonds are thus routed on the lower surface of the substrate 21, from theintegrated circuit 30 to the two end pads (not shown) of the coilantenna 40. From there, they are routed to the corresponding via holes,connecting from the lower surface to the upper surface of the substrate21, so as to make electrical contact with the separate contacts 31residing on the upper surface of the substrate. Finally, the substrate21 is encapsulated using known techniques so that the resulting chipcarrier module 10 is amenable to machine assembly without demand forfurther electrical connections. The chip carrier module 21 is mounted onto the support medium 20 until the shoulders 27 of the substrate 20 abuta corresponding shoulder of the support medium, thereby bringing theupper side of both card and module flush with each other. The spatialdisposition of the cavity 22 relative to the support medium 20 as wellas the dimensions and separation of the individual contacts are selectedso that the contact field conforms to ISO 7816.

FIG. 7 shows schematically the lower surface of the substrate 21 withthe coil antenna 40 mounted on a peripheral shoulder 27 thereof.Likewise, a second coil antenna 41 connected in series with the firstcoil antenna 40, is mounted on the upper surface of the substrate 21.The integrated circuit 30 is wire-bonded to the first end of the firstcoil antenna 40, on the lower surface of the substrate 21. The secondend of the first coil antenna 40 is connected via a first plated throughhole 42 to the first end of the second coil antenna 41 (shown in dottedoutline) located on the upper surface of the substrate. Likewise, thesecond end of the second coil antenna 41, also on the upper surface ofsubstrate 21, is connected via a second plated through hole 43 whichitself is wire bonded to the integrated circuit 30. Such a doubleantenna provides an augmented captive area and thus achieves enhancedcommunication performance.

It is also possible to exploit the capacitance inherent between the twocoil antennae 40 which behave as a parallel plate capacitor to tune thechip carrier module 10 to a desired working frequency, such as theresonant frequency of a data reader antenna. The operational frequencyof the coil antennae is a function of the capacitance between the twocoils. This avoids the separate connection to a discrete capacitorthereby reducing the bulk of the tuned circuit. Nevertheless, ifdesired, an additional external capacitor may be connected to the chipcarrier module 10, in order to provide for the necessary tuning.

Whilst a preferred embodiment of the invention has been described indetail, it is apparent that may modifications and variations thereto arepossible, all of which fall within the true spirit and scope of theinvention. For example, if desired the integrated circuit 30 may beoffset relative to the middle of the substrate 21. Also, otherconfigurations are possible for the coil antenna 40 which may be adaptedto suit microwave transmission.

What is claimed is:
 1. A data transaction card having an interface forbi-directional contactless communication, the data transaction cardcomprising: a support having a cavity for accommodating therein a chipcarrier module which comprises: a substrate having a first side and asecond side, an integrated circuit mounted on the first side of thesubstrate for managing functions of the data transaction card, and acoil antenna formed in the substrate around the integrated circuit andelectrically connected via the substrate to the integrated circuit forinductive coupling with a remote antenna, connections to the coilantenna being accessible from the first side of the substrate; the chipcarrier module being packaged into one discrete unit so as to beamenable to mechanical assembly of the data transaction card withoutrequiring additional electrical connections between the coil antenna andthe chip carrier module during or subsequent to assembly.
 2. The datatransaction card according to claim 1, further comprising: an opticalvisual authentication mark applied to the second side of the substrate,so as to remain visible after packaging into the chip carrier module andafter assembly of the chip carrier module with the support.
 3. The datatransaction card according to claim 2, wherein the visual authenticationmark is a hologram.
 4. The data transaction card according to claim 2,wherein the visual authentication mark is an encoded hologram whichforms a personal identification of an authorized bearer of the datatransaction card.
 5. The data transaction card according to claim 4,wherein the encoded hologram is a picture of the authorized bearer ofthe data transaction card.
 6. The data transaction card according toclaim 1, wherein the substrate further comprises: a contact field withseparate contacts applied on the second side of the substrate, forcontact communication between the data transaction card and a cardreader.
 7. The data transaction card according to claim 6, wherein thecontact field conforms to ISO
 7816. 8. The data transaction cardaccording to claim 6, wherein the cavity is spatially disposed relativeto the support so that when the chip carrier module is assembled on tothe support, the contact field conforms to ISO
 7816. 9. The datatransaction card according to claim 6 wherein contact field isdimensioned so as to increase the effectiveness of the coil antenna. 10.The data transaction card according to claim 6 having an overallthickness no greater than 0.8 mm.
 11. The data transaction cardaccording to claim 1, wherein the coil antenna is applied on the firstside of the substrate.
 12. The data transaction card according to claim11, further comprising: a second coil antenna mounted on the second sideof the substrate and being connected to the first coil antenna and tothe integrated circuit by electrical interconnections passing from thefirst side of the substrate to the second side thereof.
 13. The datatransaction card according to claim 12, wherein the first and secondcoil antennae are provided each with a different number of windings. 14.The data transaction card according to claim 13, wherein: the first andsecond coil antennae behave as a parallel plate capacitor, and anoperational frequency of the coil antennae is a function of acapacitance of said parallel plate capacitor.
 15. The data transactioncard according to claim 12, wherein: the first and second coil antennaebehave as a parallel plate capacitor, and an operational frequency ofthe coil antennae is a function of a capacitance of said parallel platecapacitor.
 16. The data transaction card according to claim 1, whereinthe coil antenna is applied on to the second side of the substrate, andis connected to the integrated circuit by electrical interconnectionspassing from the first side of the substrate to the second side thereof.17. The data transaction card according to claim 1, wherein the coilantenna is applied along a periphery of the chip carrier module.
 18. Amethod for manufacturing a data transaction card, said method includingthe steps of: (a) providing a support having a cavity therein, (b)independently producing a chip carrier module including a substratehaving a coil antenna formed therein around an integrated circuitmounted on the substrate and connected via the substrate to the coilantenna, and (c) mounting the chip carrier module in the cavity of thesupport.